To be honest, I've been vaping for 10 years and am rather 'old school' in my preferences. I'm not a 'cloud chaser', I just want it to be like smoking.
I get my stuff from Vapor 4 Life in the US, not the cheapest option to be sure. I started with the Vapor Titan then progressed to a Vapor Zeus + Smileomizers. I use these because you can get draw activated (you don't need to press a button) and it gives me the feeling of having a 'drag', which I haven't found with other types. There are draw activated units around now, and I personally recommend them to give a more realistic smoking feel.
Personally I've tried other systems but they didn't work for me, I felt like I was drinking the juice because I suck hard.
I vape a menthol tobacco blend, I've found the Juice Factory good for premixed concentrates that you add to your base liquid mixed with your preferred level of nicotine. Works for me. Finding a tobacco taste can be hard. If you've got the money, V4L make a real tobacco juice which you can buy in different nic levels. They don't sell concentrates, so it is expensive depending on the US-AUD exchange rate.
Personally I have found that Australian premixed juices are far too sweet for my taste, partly because they use a higher Vegetable Glycol to Propylene Glycol ratio. Perhaps that is why so many Aussies like the fruit & bakery flavours.
I suspect vaping unflavoured liquid works best if you use a higher nicotine content, because otherwise I don't understand where the 'hit' is coming from. I vape low nicotine levels, so I need the flavour to help with that smoking taste.
I'm not affiliated with V4L in any way, I've just found them & their products give me what I need.
I really couldn't say what it costs me a month to vape. Way less than $43 per day, though, that's for sure!
Good luck in your vaping journey.